Objects and Subsurfs

So, I’m modeling a gun. I need the main part to be curved and smooth (why I’m using subsurfs). I made it with a plane. I added a cylinder for the barrel, but it’s still being considered “OB:Plane” so it’s getting the subsurf modifier as well. Is there any way I can select only the vertices’ I want to have the modifier, or do I have the wrong approach completely?

Modifiers can only be applied to objects. You have to add objects separately in object mode. To separate a piece of mesh into its own object you can press P. You can also use edgesplit and crease and sharp to limit subsurf on parts of a mesh. It talks about these here: